With the continuous improvement of network bandwidth, the continuous development of terminal equipment, high-definition video conferencing, cloud services, mass data exchange, mobile office, etc., enterprises become more efficient and more open platform, thus promoting the intelligent and information office of enterprises, and the requirements for network bandwidth and speed are becoming higher and higher.Traditional enterprise and campus Lans have the demand of network upgrade when facing the huge challenge of bandwidth from these applications.
The composition of an all optical network
POL uses the PON technology, Passive Optical Network (PON) is a point-to-multi point (P2MP) Passive Optical Network, which consists of OLT(LM808E), ODN, and ONT.
POL(Passive Optical LAN)Passive all-optical LAN
In POL networking, aggregation switches in traditional LAN are replaced by OLT(LM808E). Horizontal copper cable is replaced by optical fiber; Access switches are replaced by passive optical splitter.
The ONT provides layer 2 or Layer 3 functions to access users' data, voice, and video services through wired or wireless devices.
PON network downlink adopts broadcast mode: the optical signal sent by OLT(LM808E) is divided into multiple optical signals with the same information through an optical splitter and sent to each ONT;The ONT selectively receives its own packets based on the tags in the packets and discards those with inconsistent Tag.
Uplink direction of PON network: The OLT(LM808E) allocates a time slice to each ONT. The ONT sends signals strictly according to this time slice and shuts down the optical port based on the time slice that does not belong to it. The uplink time window scheduling mechanism is highly dependent on the ranging technology of the PON.
The understanding of the principle of PON technology helps us to apply this technology more skillfully in electrical design, especially the passive (no power supply) characteristics of optical distribution network, and the difference between traditional switch point distribution design in particular need to pay attention to.To ensure that traffic packets in two directions are forwarded on one core fiber, PON adopts wave-division mode.After the development to 10 Gigabit PON, four wavelength segments are used for optical fiber multiplexing.
Optical world, Limee Solution! Let's continue our discussion of the all optical world next time.
Post time: Jan-13-2022
